The impact of convective flow on thermal diffusion cloud chamber operation

We report here new results that further elucidate the role of buoyancy-driv en convective flows in determining the distribution of vapor mole fraction and temperature in the thermal diffusion cloud chamber. A two-dimensional m odel describing both diffusion and convection in the presence of chamber si dewalls is presented. The model equations are used to analyze 1-butanol and I-pentanol nucleation data obtained earlier. The results of the investigat ion show that convective flow is nearly always present and, in the cases co nsidered here, result in a reduction in the value of the calculated critica l supersaturation (as compared to the one-dimensional case). The dependence of critical supersaturation with total pressure reported earlier is smalle r but is not eliminated.